package com.container.demo;

import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;

public class LinkedHashSetTest {
    public static void main(String[] args) {
        LinkedHashSet<String> set = new LinkedHashSet<>();
        set.add("1");
        System.out.println(set);

        set.add(null);
        System.out.println(set);
    }
}
